package com.pfizer.DownLoad;

import java.io.File;
import java.io.RandomAccessFile;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.UUID;
import java.util.concurrent.ConcurrentHashMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import com.pfizer.DB.DataHelper;
import android.util.Log;

/**
 * FileDownloader--<b>文件下载<b>-- 根據URL啟動多線程下載文件
 * 
 * @author 樊相奎
 * @version 2.45 2011/11/19
 */
public class FileDownloader {
	private static final String TAG = "FileDownloader";
	// 定義文件下載變量
	private DataHelper dHelper;
	private String downloadUrl;
	private int downloadSize = 0;
	private int downType = 0;
	private long parentID = 0;
	private int fileSize = 0;
	private File saveFile;
	private int block;
	// 定義下載線程
	private DownloadThread[] threads;
	// 各個下載線程已經下載的數據大小
	private Map<Integer, Integer> data = new ConcurrentHashMap<Integer, Integer>();

	/**
	 * getThreadSize--<b>線程數<b>-- 取得當前下載文件的線程數
	 */
	public int getThreadSize() {
		return threads.length;
	}

	/**
	 * getFileSize--<b>文件大小<b>-- 取得當前下載文件的大小
	 */
	public int getFileSize() {
		return fileSize;
	}

	/**
	 * append--<b>下載大小<b>-- 添加當前下載文件的已經下載大小
	 */
	protected synchronized void append(int size) {
		downloadSize += size;
	}

	/**
	 * update--<b>更新線程已經下載大小<b>--
	 */
	protected void update(int threadId, int pos) {
		this.data.put(threadId, pos);
	}

	/**
	 * FileDownloader--<b>文件下載類構造函數<b>--
	 * 
	 * @param context
	 * @param downloadUrl
	 *            :下載地址;
	 * @param fileSaveDir
	 *            :本地保存文件;
	 * @param threadNum
	 *            :線程數;
	 */
	public FileDownloader(DataHelper helper,
			String downloadUrl, File fileSaveDir, int _downType,
			long _parentID, int threadNum) {
		try {
			// 初始化文件下載參數
			//this.context = context;
			this.downloadUrl = downloadUrl;
			this.downType = _downType;
			this.parentID = _parentID;
			this.dHelper = helper;
			URL url = new URL(this.downloadUrl);
			// 判斷本地保存文件是否存在
			if (!fileSaveDir.exists()) {
				fileSaveDir.mkdirs();
			}

			// 進行下載URL鏈接，取得數據
			HttpURLConnection conn = (HttpURLConnection) url.openConnection();
			conn.setConnectTimeout(30 * 1000);
			conn.setRequestMethod("GET");
			conn.setRequestProperty(
					"Accept",
					"image/gif, image/jpeg, image/pjpeg, image/pjpeg, application/x-shockwave-flash, application/xaml+xml, application/vnd.ms-xpsdocument, application/x-ms-xbap, application/x-ms-application, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*");
			conn.setRequestProperty("Accept-Language", "zh-CN");
			conn.setRequestProperty("Referer", downloadUrl);
			conn.setRequestProperty("Charset", "UTF-8");
			conn.setRequestProperty(
					"User-Agent",
					"Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.2; Trident/4.0; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30; .NET CLR 3.0.4506.2152; .NET CLR 3.5.30729)");
			conn.setRequestProperty("Connection", "Keep-Alive");
			conn.connect();
			printResponseHeader(conn);
			if (conn.getResponseCode() == 200) {
				// 鏈接成功，設置下載相關參數
				this.fileSize = conn.getContentLength();
				if (this.fileSize <= 0)
					throw new RuntimeException("Unkown file size ");

				String filename = getFileName(conn);
				this.saveFile = new File(fileSaveDir, filename);
				if(this.saveFile.exists())
				{
					this.saveFile.delete();
				}
				
				this.threads = new DownloadThread[threadNum];
				this.block = (this.fileSize % this.threads.length) == 0 ? this.fileSize
						/ this.threads.length
						: this.fileSize / this.threads.length + 1;
				if (this.data.size() == this.threads.length) {
					for (int i = 0; i < this.threads.length; i++) {
						this.downloadSize += this.data.get(i + 1);
					}
				}
			} else {
				throw new RuntimeException("1");
			}
		} catch (Exception e) {
			throw new RuntimeException("1");
		}
	}

	/**
	 * getFileName--<b>取得下載文件<b>--
	 */
	private String getFileName(HttpURLConnection conn) {
		String filename = this.downloadUrl.substring(this.downloadUrl
				.lastIndexOf('/') + 1);
		if (filename == null || "".equals(filename.trim())) {
			for (int i = 0;; i++) {
				String mine = conn.getHeaderField(i);
				if (mine == null)
					break;
				if ("content-disposition".equals(conn.getHeaderFieldKey(i)
						.toLowerCase())) {
					Matcher m = Pattern.compile(".*filename=(.*)").matcher(
							mine.toLowerCase());
					if (m.find())
						return m.group(1);
				}
			}
			filename = UUID.randomUUID() + ".tmp";
		}
		return filename;
	}

	/**
	 * download--<b>文件下載<b>-- 設置監聽器以便在主程式中隨時取得已經下載的數據大小
	 * 
	 * @param listener:文件下載監聽器
	 */
	public int download(DownloadProgressListener listener) throws Exception {
		try {

			RandomAccessFile randOut = new RandomAccessFile(this.saveFile, "rw");
			if (this.fileSize > 0)
				randOut.setLength(this.fileSize);
			randOut.close();
			URL url = new URL(this.downloadUrl);
			if (this.data.size() != this.threads.length) {
				this.data.clear();
				for (int i = 0; i < this.threads.length; i++) {
					this.data.put(i + 1, 0);
				}
			}
			for (int i = 0; i < this.threads.length; i++) {
				int downLength = this.data.get(i + 1);
				if (downLength < this.block
						&& this.downloadSize < this.fileSize) {
					this.threads[i] = new DownloadThread(this, url,
							this.saveFile, this.block, this.data.get(i + 1),
							i + 1);
					this.threads[i].setPriority(7);
					this.threads[i].start();
				} else {
					this.threads[i] = null;
				}
			}
			this.dHelper.addDownLog(this.downloadUrl, this.downType,
					this.parentID, this.saveFile.getPath());
			boolean notFinish = true;
			while (notFinish) {
				Thread.sleep(900);
				notFinish = false;
				for (int i = 0; i < this.threads.length; i++) {
					if (this.threads[i] != null && !this.threads[i].isFinish()) {
						notFinish = true;
						if (this.threads[i].getDownLength() == -1) {
							this.threads[i] = new DownloadThread(this, url,
									this.saveFile, this.block,
									this.data.get(i + 1), i + 1);
							this.threads[i].setPriority(7);
							this.threads[i].start();
						}
					}
				}
				if (listener != null)
					listener.onDownloadSize(this.fileSize, this.downloadSize);
			}
			dHelper.deleteDownlogByPath(this.downloadUrl);
		} catch (Exception e) {
			print(e.toString());
			throw new Exception("file download fail");
		}
		return this.downloadSize;
	}

	/**
	 * getHttpResponseHeader--<b>获取響應的http文件頭<b>--
	 * 
	 * @param http:URL文件鏈接
	 * 
	 * @return Map<String, String>:返回文件Header Map
	 */
	public static Map<String, String> getHttpResponseHeader(
			HttpURLConnection http) {
		Map<String, String> header = new LinkedHashMap<String, String>();
		for (int i = 0;; i++) {
			String mine = http.getHeaderField(i);
			if (mine == null)
				break;
			header.put(http.getHeaderFieldKey(i), mine);
		}
		return header;
	}

	/**
	 * printResponseHeader--<b>打印顯示響應的http文件頭<b>--
	 * 
	 * @param http:URL文件鏈接
	 */
	public static void printResponseHeader(HttpURLConnection http) {
		Map<String, String> header = getHttpResponseHeader(http);
		for (Map.Entry<String, String> entry : header.entrySet()) {
			String key = entry.getKey() != null ? entry.getKey() + ":" : "";
			print(key + entry.getValue());
		}
	}

	private static void print(String msg) {
		Log.i(TAG, msg);
	}

}
